I mean... I have a Fin Fang Foom baf figure on my shelf that serves the purpose.   I don't need them to revisit him.   But if they did -  and it were not $350 or whatever -  I'd probably cave.     I'd rather get a Devil Dinosaur and Moon Boy set though.

Sure, I'd buy another Foom if they made a bigger and better one, but since I have the BAF it wouldn't be a priority to me to get made. 

Like @PantherCult said, there are other things I'd rather them spend their time on.

For me personally, I really want some type of representation of Krakoa the Living Island.

I bought a red Mattel Jurassic World T-Rex as that's my stand if for Devil Dino right now with the Marvel Universe 1/18th scale Moon Boy riding him (which makes Dino look bigger). They've made a significantly bigger T-Rex for the new movie that I hope they eventually do a red variant of as well. Regardless, I'd still buy an official Legends Devil Dino though. 

Another one that I'd really like to see is Giganto the Mole Monster. Since he appears in this month's movie, I'm hoping that might help make that happen. Pack him with a new Mole Man and some Moloids/Subterraneans and that's an instant buy. 

It the Living Colossus or a Celestial like Arishem the Judge or Ziran the Tester would be high on my list as well. 

Personally I'd welcome a Made-to-Order Marvel Legends Fin Fang Foom. Heaven know we all need him in our collection to build that world of Marvel, regardless to the fact that he's not that popular a character like someone like Mandarin is.